Process of preparing solutions for the treatment of steel.



lenient BENTON KNOTT J'AMISON, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO NATIONAL STEEL REEINING COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

PROCESS OF PREPARTNG SOLUTIONS FOR THE TREATMENT OF STEEL.

SPECIFICATION forming part of Letters Patent No. 690,963, dated January 14, 1902.

Original application filed December 24, 1897, Serial No. 663,28 Divided and application filed June'l6, 1900, Serial No. 20,565.

Again divided and this application filed August 26, 1901. Serial No. 73,261. (No specimens.)

Zl'o all whom it may concern:

Be it known that I, BENTON KNOTT J AMI- SON, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Processes of Preparing Solutions for the Treatment of Steel, of which the following is a specification.

This application is a division of my application filed June 16, 1900, Serial No. 20,565, and is in part a division of my application filed December 24, 1897, Serial No. 663,284.

In my said applications I have described a method of treating armor-plates, which consists in heating a steel plate, preferably of low-grade or mild open-hearth steel, slowly and gradually until it attains a bright-red heat and then with as little delay as practicable immersing it to a depth corresponding to the depth which is required to be hardened in a cold bath of a hardening solution which is capable of yielding hydrocarbon gases and maintaining the bath as nearly as practicable at a temperature of to Fahrenheit, while permitting the plate to remain in the bath for a sufficient length of time to effect the hardening process, the hardened portion of the plate being toughened at its face, so that a plate of three different grades of steel may be obtained. The hardening solution or bath therein described comprises the following ingredients in the proportions named: sweet spirits of niter, (B. P. three ounces; aqua-ammonia, (specific gravity .88,) three ounces; chlorid of ammonium, six ounces; sulfate of zinc, three ounces; ground alum, (AI SSQ Am S Z IH O,) three ounces; glycerin, eight ounces; Water, one gallon. It is important, however, that the ingredients of my improved hardening solution shall be mixed in a certain order and that certain amounts of time shall be allowed to elapse between the additions of the several ingredients.

The present invention relates to the process of combining the ingredients of the solution.

It is especially important that the ground alum, sulfate ofzinc, water, and glycerin shall go be mixed in the manner stated whether the other ingredients are so mixed or not and Whether the other ingredients are used exactly as specified or are replaced by substitutes therefor or are omitted entirely.

I first introduce into the water the ground alum and the sulfate of zinc, and I allow the mixture to stand for about twelve hours or longer. I then add the glycerin and afterward as soon as practicable the other ingre- 60 clients. When all the ingredients have been added and thoroughly mixed, it is desirable to allow the mixture to stand forabouttwentyfour hours before use. In addition to the above ingredients I prefer to add one ounce 65 each of sulfate of copper and nitrate of soda, and in this case these ingredients are introduced after the addition of the glycerin. In order to prevent too-rapid evaporation of the solution in use, I prefer to add sufficientma- 7o chine-oil to cover the surface of the bath.

It is found that by the treatment of lowgrade steel as described with the hath made after my improved process it is changed in nature, physical structure, and molecular construction, whereas steel tempered in oil is simply tempered more slowly than by the use of water or other agents and leaves the steel less hard though somewhat tougher than Water-tempered material. Furthermore, the changes induced in the steel by a hath made according to my improved process are permanent-that is to say, the treated plates can be reheated, forged, and reforged Without changing their nature, physical structure, or molecular constructionwhich is a decided advantage over oi l-tem pering processes,whose effects are merely temporary and capable of being neutralized by reheating and allowing the metal to cool.

The process can be modified by varying the quantity of water used; but I have found in practice that the proportions speci fied give the best results.

What I claim is l. The herein-described method of mixing solutions for the treatment of steel contain ing ground alum, sulfate of zinc, water and glycerin, which consists in first introducing the alum and sulfate into the water, maintaining such mixture in a state of rest for approximately twelve hours, and then adding the glycerin.

2. The herein-described method of mixing solutions for the treatment of steel containing ground alum, sulfate of zinc, water, glycerin and other ingredients, which consists in first introducing the alum and sulfate into the water, maintaining such mixture in astate of rest for approximately twelve hours, then adding the glycerin and otheringredients,an d maintaining the resultant solution in a state of rest for approximately twenty-four hours before using.

The herein-described method of making a solution for the treatment of steel which consists in first introducing three ounces of ground alum and three ounces of sulfate of zinc into one gallon of water,'1naintaining such mixture in a state of rest for approximately twelve hours, then adding glycerin, eight ounces; chlorid of ammonium, six ounces; aqua-ammonia, three ounces;and sweet spirits of niter, three ounces.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

BENTON KNOTT JAMISON.

Witnesses:

A. REYNOLDS COLESBERRY, FRANK M. WIRGMAN. 

